Omicron-aryl omicron-methyl phosphoroamido-thioates



United States Patent O-ARYL O-METHYL PHOSPHOROAMIDO- THIOATES Kenneth C.Kauer and Edgar C. Britton, Midland, Mich., assignors to The DowChemical Company, Midland, Mich, a corporation of Delaware No Drawing.Application April 2, 1956 Serial No. 580,427

6 Claims. (Cl. 260-461) The present invention is concerned with novelO-aryl O-methyl phosphoroamidothioates of the following formula in thisand succeeding formulae, X represents chlorine or bromine and Rrepresents hydrogen, methy or ethyl. These compounds are viscous liquidswhich are somewhat soluble in many organic solvents and of very low withammonia, methylamine or ethylamine. The reaction is exothermic and takesplace smoothly at the temperature range of from 10 to 30 C. with theformation of the desired product and ammonium hydrochloride or aminehydrochloride of reaction. The temperature may be controlled byregulating the rate of contacting the reactants and by external coolingas may be required. The reaction is carried out in the presence of asolvent such as acetone, methyl ethyl ketone, carbon tetrachloride orbenzene. In a preferred operation, the reaction is carried out withaqueous ammonia or aqueous amine and in a Water miscible solvent. Goodresults are obtained when at least two molecular proportions of ammoniaor amine is reacted with each molecular proportion of thephosphorochloridothioate reagent.

In carrying out the reaction, gaseous ammonia or alkyl amine iscontacted with the O-aryl O-methyl phosphorochloridothioate at atemperature of from -10 to 30 C. This operation is carried out in thepresence of one or more of the aforementioned solvents. In analternative procedure, an aqueous solution of ammonia or alkyl amine ismixed and blended with the phosphorochloridothioate reagent dispersed ina solvent such as acetone. Following the reaction, the reaction mixtureis washed with water to separate water soluble salts and solvent andobtain the desired product as a viscous liquid.

The following examples illustrate the invention and are not to beconstrued as limiting.

EXAMPLE I O-(4-tertim'ybutyl-Z-chlorophenyl) (D-methylphosphoroamidothioate O-(4-tertiarybutyl-2-chlorophenyl) O-nethylphosphorochloridothioate (62.5 grams, 0.2 mole) was dispersed in2,836,612 Patented May 27, 1958 milliliters of acetone and 30 grams of a25 percent aqueous solution of ammonia added portionwise thereto withstirring. The addition was carried out over a period or" one hour and ata temperature of from 3 to 7 C. Following the reaction, the reactionmixture was diluted with 300 milliliters of water and the dilutedmixture thereafter extracted with methylene chloride. The extract wasthen dried with sodium sulfate, filtered and the filtrate distilledunder reduced pressure at temperatures gradually increasing up to atemperature of 65 C. to separate the solvent. As a result of theseoperations, there was obtained an O-(4-tertiarybutyl-2-chlorophenyl)O-methyl phosphoroamidothioate product as a liquid residue. This producthad a density of 1.241 at 25 C., a refractive index n/D of 1.5562 at 25C. and a phosphorus content of 10.39 percent and nitrogen content of4.73 percent. Theoretical values for phosphorus and nitrogen are 10.5and 4.77 percent, respectively.

EXAMPLE II O-(4-tertiarybutyl-Z-bromophenyl) 0-methyl phosphoroamidothioate Thirty grams of 26 percent aqueous ammonia was addeddropwise over a period of one hour to a mixture comprising 53.5 grams(0.15 mole) of O-(4-tertiarybutyl-2-bromophenyl) O-methylphosphorochloridothioate dissolved in 100 milliliters of acetone. Theaddition was carried out with stirring and cooling in ice and at atemperature of from 3 to 7 C. Following the addition, the reactionmixture was diluted with 300 milliliters of water, the diluted mixtureextracted with methylene chloride and the methylene chloride extractdried over sodium sulfate. The dried extract was then filtered and thefiltrate concentrated by distillation under reduced pressure attemperatures gradually increasing up to a temperature of C. As a resultof these operations there was obtained anO-(4-tertiarybutyl-2-bromophenyl) O-methyl phosphoroamidothioate productas an oily residue. This product had a specific gravity of 1.3976 at 25C. and a refractive index n/D of 1.5708 at 25 C.

EXAMPLE III 0-(4-tertiaiybutyl-Z-chlorophenyl) O-methyl N-methylphosphoroamidoth iomfe O-(4-tertiarybutyl-2-chlorophenyl) O-methylphosphorochloridothioate (40 grams, 0.128 mole) was dissolved in 200milliliters of benzene and a 25 percent aqueous solution of methylamine(eight grams, 0.256 mole of methylamine) added portionwise thereto withstirring. The addition was carried out with cooling and at a temperatureof from 10 to 20 C. Stirring was continued for one half hour followingthe addition and the reaction mixture thereafter washed with water. Thesolvent was then separated from the washed mixture by evaporation andthe residue thereafter concentrated by distillation under reducedpressure at gradually increasing temperatures up to a pot temperature of80 C. As a result of these operations there was obtained anO-(4-tertiarybutyl-2- chlorophenyl) O-methyl N-methylphosphoroamidothioate product as an oily residue. This product had adensity of 1.1953 at 25 C. and a refractive index n/D of 1.5468 at 25 C.

EXAMPLE IV 0-(4-tcrtiarybutyI-Z-bromophenyl) O-methyl N-ethylphosphorozzmidothioate A 25 percent aqueous solution of ethylamine (13.5grams, 0.3 mole of ethylamine) was added portionwise with stirring andcooling to 54 grams (0.15 mole) of O- (4-tertiarybutyl-2-bromophenyl)O-methyl phosphorochloridothioate dispersed in 200 milliliters ofbenzene.

, residue.

The addition was carried'out over a period of one hour and at atemperature of from 5 to 15? C. Following the addition the reaction rnigtture was washed with water 7 and thereafter dried with sodiumsulfate. The dried mixture was then distilled under reduced pressure atgradually increasing temperatures up to. a pot temperature of 67 C. toobtain an O-(4-tertiarybutyl-2-bromophenyl) methyl N-ethylphosphoroamidothioate product as an oily Thisproduct had a densityfof1.2782 at 25 C. and a refractive index r'z/D of 1.5479 at 25 C.

EXAMPLE V O-(4-tertiarybutyl-Z-chlorophenyl) O-methyl N-ethylphosphoroamidothioate a A 25 percent aqueous solution of ethylamine(13.5 grams, 0.3 mole of ethylamine) was added portionwise withstirringand cooling to 47 grams (0.15 mole) of '70-(4-tertiarybutyl-2-chlorophenyl) O-methyl phosphorochloridothioatedispersed in 200 milliliters of benzene.

The addition was carried out over a period of one hour and atetemperature of from 5 to C. Following the addition the reactionmixturewas treated as dechlorophenyl) Ormethyl N-ethylphosphoroamidothioate product as an oily liquid residue. This producthad a density of 1.1602 at C. and a refractive index n/D of 1.5371 at 25C. I

In a similar manner O-(4-tertiarybutyl-Z-bromophenyl) O-methyl N-ethylphosphoroamidothioate' may be ,pre pared by reacting0-(4-tertiarybutyl-Z-bromophenyl) 0- methyl phosphorochloridothioatewith ethylamine.

' scribed in Example 4 to obtain an O-(4 tertiarybutyl-2- The new O-arylO-methyl phosphoroamidothioate prod- 7 W i flfli v ployedas startingmaterials as herein described may be prepar by reac i g on m lecul prpor on, of .a

suitable O-aryl phosphorodichloridothioate with one molecular-proportionof sodium methylate'in an inert organic solvent such as benzene. Incarrying out the reaction, the reactive agents and solvents are mixedto-.

gether and thereafter heated'for'a periodof time at. a temperatureoffronr to 809 C; The reactionmixture is then successivelytwashed withdilute aqueous sodium'hydroxide and water and the solventthereafterseparated byevaporati'on to obtain the desired starting material as aliquid residue.

We claim: 1. An O-aryl O-methylphosphoroamidothioate of the formulawherein X represents a member of the group consisting of chlorine andbromine and R represents a member of the group consisting of hydrogen,methyl and ethyl. 2. O-(4-tertiarybutyl-2-chlorophenyl) O-methyl phos 1phoroamidothioate.

3. O-'(4-tertiarybutyl-Z-bromophenyl) O-methyl phos phoroamidothioate.

a 4; O-(4-tertiarybutylchlorophenyl) O-methyl N- methyl'phosphoroamidothioate' v 5. O-(4-tertiarybutyl 2 bromophenyl) O-rnethyl N- ethyl phosphoroamidothioate.

6. O-(4-tertiarybutyl 2 chlorophenyl) O-methyl N- ethylphosphorbamidothioate; V V K i e References Citedin the file of thispatent UNITED STATES PATENTS 2,506,344 Cleary Ma 2, 1950 FOREIGN PATENTS814,152 Germany 1Sept. 20, 1951' Switzerland Nov. 1, 1947

1. AN O-ARYL O-METHYL PHOSPHOROAMIDOTHIOATE OF THE FORMULA